This is cohort research that looks backward in time. The purpose of this research was to look at how a patient’s body mass index (BMI) and spine flexibility index (FI) affect the success of surgery for adolescent idiopathic scoliosis (AIS). During preoperative planning for AIS correction, BMI and FI are considered, but the correlation between the 2 is poorly studied. Researchers hypothesize that the surgical results for AIS patients will be worse if they have a higher body mass index. They looked at a database of AIS patients who were 11-19 years old at the time of surgery and who had posterior fusion at a single center between 2011 and 2017. Patients who lacked the necessary radiographic imaging or had a history of prior spine surgery that precluded an accurate FI assessment were not included. Patients were divided into 2 groups, 1 for each major curve segment, based on whether their FI was stiff (FI<50) or flexible (FI≥50). Overweight was defined as having a body mass index (BMI) between the 85th and 95th percentiles, and obese as having a BMI more than the 95th percentile. Intraoperative, short-term, and long-term success rates were analyzed using a regression model for correlations with BMI and FI. There were a total of 543 patients, with 82% being female and the average age being 14.9. Over the course of 2 years, data were collected for 346 patients. Patients with large thoracolumbar/lumbar curves saw a 1.3% reduction in FI for every 10% rise in BMI (P=0.01). Patients with obesity had a higher risk of complications immediately following surgery (P=0.003) and at the 2-year mark (P=0.04). After 2 years, 80% of difficulties required additional surgery (4/5), and 58% of issues within the first 2 years required additional surgery (15/26). Initial curve magnitude (P<0.001), operation duration (P=0.02), and blood loss (P=0.02) all had negative correlations with FI. When comparing patients of normal weight with stiff curves and obese patients with flexible curves, the likelihood of a postoperative complication in the obese group was 10 times higher than in the healthy group (P=0.001). Patients with significant thoracolumbar/lumbar curves had lower FI if their body mass index was high. Postoperative complications were more common in patients with both a high body mass index and a high FI.
Source: journals.lww.com/spinejournal/Abstract/2022/11010/The_Effects_of_Body_Mass_Index_and_Spine.2.aspx
